Gasoline tank overflow device



United States Patent O 3,520,329 GASOLINE TANK OVERFLOW DEVICE Karl A. Weber, R0. Box 509, Rancho Santa Fe, Calif. 92067 Filed Oct. 8, 1968, Ser. No. 775,983 Int. Cl. B65d 87/12 US. Cl. 137-571 Claims ABSTRACT OF THE DISCLOSURE A gasoline tank associated with a second tank, either internally or externally, so that when the gasoline tank is overfilled or the gasoline expands to cause excess gasoline in the main tank, this excess flows into the second tank which in turn meters this gasoline back into the main tank when this overfilled condition subsides.

BACKGROUND OF THE INVENTION When a gasoline station attendant fills a gas tank on a vehicle, he generally places the filling nozzle into the tank inlet tube and allows the gasoline to fill the tank until the nozzle automatic shut off is activated. Then he continues to fill the tank until he can visually see the gasoline in the filler tube. This practice causes gasoline to run out of the filler spout and onto the highway when the car is driven. A full tank of gas, sitting in the sun, also expands causing an overfilled condition. This particularly is true of aircraft gasoline tanks which are gen erally in the wings of the airplane and subject to a great deal of heat from the sun. This causes the gasoline to expand in the tank and overflow onto the wings of the aircraft when the tank cap is removed to visually inspect the fuel level. This overflowing gas and its subsequent evaporation causes a fire hazard as well as being wasteful.

SUMMARY OF THE INVENTION The present invention has a main storage gas tank and a smaller secondary tank associated therewith. The intake spout in the main tank is positioned so that the liquid in the tank will trigger the automatic shut off when the desired liquid level is reached, and any temporary overfill will flow into the second tank and be returned to the main tank at a controlled rate. The intake of this tank will generally be below the fuel level when the tank is full, but the intake and outlet orifices will be small so that the second tank will not fill until after the main tank has been completely filled. When the second tank fills, this will leave space in the main tank for expansion.

The principal object of the present invention is to provide a device which will accommodate excessive gasoline or other fuel caused by expansion or overfilling from being lost from the tank.

Another object of the present invention is to provide a means for returning excessive fuel to the main tank so that it can be consumed.

A further object of the present invention is toprovide a safety device which prevents fuel from leaving the main tank and becoming ignited.

DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings, where- FIG. 1 is a schematic elevation of the invention attached to a normal gas tank.

FIG. 2 is a schematic elevation showing an internal overflow tank.

FIG. 3 is a schematic elevation of anther form of the invention as illustrated'by FIG. 2.

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Referring now to the drawings, and in particular FIG. 1, which shows a main gas tank 1 which has a standard intake spout 2, and a sealer cap (not shown), and a fuel line 3 which leads onto the engine and associated parts.

In this form of the invention, a second small tank or overflow tank 4 has been added. This tank has an intake line 5 which may be located anywhere on the main tank, but preferably just below the desired liquid level. This line is small and prevents the overflow tank 4 from being filled at the same time that the main tank 1 is filled. Once the fuel level in the main tank 1 reaches the desired liquid level line 5 operates as an air vent for tank 4. After the tank is filled fuel continues to flow into the overflow tank leaving a space 9 in the main tank for expansion of the fuel. This overflow tank 4 has a return line 7 which returns this excess fuel to the main tank 1.

This form of the invention is particularly useful in that it can be added to existing fuel systems.

In the embodiment shown by FIG. 2, the overflow tank 8 is located inside of the main tank 10 and has a small metering hole 12. When excessive fuel is present it is slowly metered through these metering holes 12 and 14 into the overflow tank 8. A return metering hole 14 is provided from overflow tank 8 which returns the fuel to the main tank when the fuel reaches a level even with or just below the overflow tank. When the fuel reaches a point below metering hole 12, this hole operates as an air vent for overflow tank 8.

A third variation of the present invention is shown by FIG. 3 in which an overflow tank 20 has been welded to the top 22 of the main tank 24. This welding 26 is loosely done so that air may escape from the top of the overflow tank 20.

In the bottom of the overflow tank 20, a metering orifice 28 is provided. When an overfill situation is reached in the main tank 24 fuel flows up into the overflow tank 20, leaving an air space between the fuel level and the top of the tank for further expansion of the fuel. When this situation is remedied and the liquid level is even with or just below the metering hole 28, this excessive fuel is then allowed to drain back into the main tank.

I claim:

1. In combination with a fuel tank having an intake spout, the improvement comprising:

an overflow container mounted externally from said fuel tank;

a small inlet flow means connected between the top of the overflow container and the fuel tank; and a small outlet flow means between the bottom of said overflow container and the bottom of said fuel tank;

the size of the small inlet flow means and small outlet flow means relative to the size of the intake spout being such that during normal filling of the fuel tank substantially no fuel will flow into the overflow container whereby;

said overflow container provides an additional fuel containing reservoir operative to prevent overfilling of said fuel tank and a reservoir for storing fuel expanded by heating.

2. The combination of claim 1 wherein said small inlet means and said small outlet means are of a size so as to allow said fuel tank to completely fill before said overflow tank fills.

3. The combination of claim 1 wherein said small inlet flow means provides an air vent for said overflow tank when the fuel tank is not overfilled.

4. In combination with a fuel tank having an intake spout, the improvement comprising:

an overflow tank attached inside of and to the top of said fuel tank;

a fuell metering hole in the bottom of said overflow tan means for allowing the air to escape from the top of References Cited said overflow tank; said metering hole in said overflow tank allowing fuel UNITED STATES PATENTS to enter said overflow tank when excessive fuel is 1,382,863 6/1921 Slishman 137-576 present in the main tank and being sized With re- 5 1,732,505 10/1929 Dawson 137576 X spect to said intake spout such that during normal 1,990,605 2/ 1935 Johnson 137576 filling of said fuel tank substantially no fuel will 2,719,583 10/1955 M li k 137-576 X flow into said overflow tank whereby; said overflow tank provides an additional fuel containing reser- FOREIGN PATENTS voir operative to prevent overfilling of said fuel tank 10 968,647 9 /1964 Great B i i and a reservoir for storing fuel expanded by beating and the incoming fuel forces air out of the top of WILLIAM R. CLINE, Primary Examiner said overflow tank.

5. The combination of claim 4 wherein: US. Cl. X.R.

the means for allowing the air to escape from the top 15 2805 of said overflow tank comprises a porous weld. 

